cannot be the subject of VARA claims. And speaking of works made for hire, you need to be confident that your husband was neither a qualifying independent contractor (with a signed transfer of rights), nor an employee.
If your husband is owner ... Assuming your husband can demonstrate ownership, you should contact a copyright attorney. Both of the scenarios you discuss are infringements and more importantly, the entities committing these infringements appear to be deep-pocketed. In other words, the potential damages may justify the financial costs of pursuit. In order to pursue copyright litigation, you will need to register the works with the Copyright Office (although no registration is required if only the VARA claims are made).
What's VARA? The Visual Artists Rights Act (VARA) amended the Copyright Act to provide artists with attribution (the right to take or not take credit) and integrity (the right to prevent distortion, modification or mutilation). As for destruction, VARA does not apply if your husband's mural was created (or installed as a mural) before December 1990, or if your husband waived his rights in a written agreement, or the destruction occurs naturally (due to the effects of time or the composition of the materials). When artwork is incorporated in a building and the owner plans to modify the building (which will affect the artwork), the owner must provide the mural artist with notice so that the artist has the opportunity to remove the work, or pay someone to remove it. (In order to insure that notice is received by the artist, the Register of Copyright was supposed to establish a system whereby the artist may record identifying information at the Copyright Office. However we were unable to uncover any evidence that the registry was ever created.)
What does VARA protect? VARA only applies to “works of visual art” defined as: (1) a painting, drawing, print, or sculpture, existing in a single copy, in a limited edition of 200 copies or fewer that are signed and consecutively numbered by the author, or, in the case of a sculpture, in multiple cast, carved, or fabricated sculptures of 200 or fewer that are consecutively numbered by the author and bear the signature or other identifying mark of the author; or (2) a still photographic image produced for exhibition purposes only, existing in a single copy that is signed by the author, or in a limited edition of 200 copies or fewer that are signed and consecutively numbered by the author. You can read more about VARA here and here.